Auxiliary air inlet valve



June 116, 193%. R ABBOTT 2,044,342-

AUXILIARY AIR INLET VALVE Filed March 30, 1933 Patented June 16, 1936 EJNETED STATEfi 2,044,342 AUXILIARY AIR INLET VALVE Robert N. Abbott, Philadelphia, Pa., assignon by direct and mesne assignments, to- Manifold Vacuum Valve Corporation, a corporation of Pennsylvania Application March 30, 1933, Serial No. 663,514

1 Claim.

My device allows air to enter the intake manifold of an internal combustion engine between the throttle of the carburetor and the branches leading from the manifold to the cylinders. It

limits the amount of air passing through it into the manifold permitting a much larger amount of air to pass when the motor is at working speed, and a less amount of air to pass through it when the motor is being started or for other reason is not driving machinery, commonly called idling.

The device will smoothen the operation of the engine, and increase its power, and smartness of action, the latter being usually called pep,

save gasoline, and to an extent, diminish carbonization, by breaking up still more minutely the particles of fuel that have passed through the Venturi. There are other advantages that will be perceived by a person skilled in the art, upon reading the specification. The device comprises a cylinder in which moves a piston, that is springingly urged into the position where the air is more freely admitted through the device, and. a channel leading from the cylinder of the device to the manifold by means of which the increase of the vacuum in the manifold may be made to act upon the piston to move it against the spring into a position where the air is less freely admitted through my device into the manifold. The structure by which this is accomplished has the channel that leads from the cylinder to the manifold capable of allowing a greater volume of air to pass from the side of the piston nearer the manifold to the latter than can pass through the opening in the piston that is in communication with the exterior air. The piston has means also for closing completely or sufiiciently the inlets through which the exterior air enters the cylinder when the piston is drawn by the vacuum in the manifold in opposition to the impulse of the spring.

The device is made operative because of the conditions that exist in an internal combustion engine. When the engine is idling the vacuum in the intake manifold is greatest. When the fuel is more freely admitted, (opening the throttle, for instance) the draw in the Venturi section is increased, but the vacuum in the intake manifold becomes less, especially after the engine begins to carry its load. Naturally, therefore, the pull against the spring decreases and the piston takes a position to admit air much more freely to the manifold.

Describing now the best form of structure of which I am at present aware, but not limiting my invention thereby to this particular form, which, however, is the form put forth in the trade:

Fig. 1 is an elevation of what I consider the best form of structure embodying my invention when the piston is at the substantially closed end of the cylinder. Fig. 2 is an elevation of said structure when the piston is drawn away from the substantially closed end of the cylinder. Fig. 3 is an elevation of the piston of such structure. Fig. 4 is a section on line 44, Fig. 1.

A cylinder 1 is fitted with a screw nipple 2. Through this screw nipple a hole a is drilled into the interior of the cylinder I, and a hole or series of holes 0, c, the hole a being of much greater capacity than the combined capacity of the holes 0, c. The holes b, b, in the walls of the cylinder I may be of any desired number. The piston 3 has the depression 4 and the parts 5 and 6 that fit snugly in the cylinder I, but not so snugly that they cannot slide in it.

This piston has the holes d, d, leading from the depression 4 to the central hole I, which debouches at the end I of the piston (the end towards the exhaust manifold). The relative size and construction of the parts is such as will cause the suction of the exhaust manifold, when strong, to draw from the space A, through the hole a, a larger amount of air than can be supplied through the holes c, c, and the hole 7. The piston 3 has also a rod 8 around which is the compensating spring 9, which rests at one of its ends on the head I9 of the cylinder l, and for which an adjusting nut 20 forms the other abutment. As an aid to the mechanic who would construct an actual device, the following dimensions have been found workable in practice. Interior diameter of the cylinder, length 1 to nipple, hole in nipple, holes 0 #53 drill (four holes), hole #30 drill deep, holes, (1, d, (four) #36 drill, length of piston 5. Stubbs steel wire gage for twist drills was used for determining the size of the drills in the preceding example. The depression 4 may be turned down 3/64" and may be V wide. The rod 8 fits loosely enough in the hole in the top H! of the cylinder l, to permit enough air to pass to allow the piston to descend. The entire description above of the best form of my invented structure is, however, not to be taken as limiting my invention to less than the matter of my claim.

When the device is attached to the manifold and the engine idles, the strong suction in the manifold will draw the piston against the adjusting spring until the inlet ports leading to the piston are closed, limiting the amount of air entering through the device. When the engine is running under load, the suction in the manifold decreases and the spring draws the piston into position to allow a freer passage of air through the piston.

I claim:-

An air control device for intake manifolds of. internal combustion engines, comprising a cylinder having a nipple for attachment to the manifold, a normally open spring pressed piston valve in said cylinder, a main air inlet passage near one end of the cylinder and an outlet through the other or nipple end of the cylinder, an auxiliary air inlet passage in the nipple in constant communication with the outlet passage therein, said piston valve having a passage therethrough providing communication between the cylinder and main inlet passage during normal operation and a head adapted to close said main inlet passage upon predetermined movement of the piston valve, the air carrying capacity of the outlet passage being larger than the total capacity of the main and. auxiliary air inlet passages whereby minor fluctuations of air pressure will be without effect on the open position of the piston valve while a major fluctuation in pressure will cause the piston valve to move into position to close the main air inlet passage.

ROBERT N. ABBOTT. 

